Life under ice in the perennial ice‐covered Lake Glubokoe in Summer (East Antarctica)

This study focuses on hydrological and biotic variables in Lake Glubokoe, which is located in Thala Hills of Enderby Land (East Antarctica). Water and sediment samples and physical measurements were collected once a week in the austral summer (19 December 2010 – 6 February 2011). This lake exhibits perennial ice cover that reached a thickness of 2.5–2.7 m during the study period. A very low concentration of planktonic chlorophyll‐a (0.06–0.45 μg L^?1) was measured in the lake, indicating its ultra‐oligotrophic status. The water was poorly populated by algae and metazoans, especially in upper waters below ice cover to a depth of 2 m. Small planktonic organisms (2–5 μm) were observed throughout the study period, but larger organisms (>8 μm) such as the cyanobacteria Planktolyngbya limnetica occurred only during the warmest period (January). Only few individuals of metazoans (rotifers) were found in planktonic samples. Due to deep light penetration (10–15% of incoming active solar radiation reached the depth of 30 m), thick cyanobacterial mats (30 cm) cover all the bottom surface (grey silts) in the lake. Abundant benthic biota associated with these mats was found (up to 1000 ind. m^?2). Among the benthic metazoans, bdelloid rotifers and tardigrades were the dominating taxa. The results of this study suggest a typical ecological feature of most subglacial lakes in East Antarctica is that metazoans are very poor in the pelagic zone, preferring instead to occupy an area near the lake bottom because of a favourable constant temperature of 4 °C, good level of dissolved oxygen and available food resources as the bacterial detritus.     

Pulsed Laser Precision Length Measurements

The paper discusses mode locking use in pulsed lasers for precision measurement of large lengths.     

Algorithms for synchronization of spatial diversity clocks from the signals of satellite navigation systems

Algorithms for synchronization of spatial diversity clocks from the signals of satellite navigation systems are presented. Synthesis of the algorithms is based on methods of estimating the augmented state vector of a dynamical object.     

Improvement in the orbital parameters of GLONASS navigation satellites based on non-interrogatory measurements of pseudodistances

A method is described for improving the accuracy of the orbital parameters of navigational satellites employing noised measurements of pseudodistances and minimization of deviations. Computer simulations demonstrate the efficiency of this method.     

Health and wellness monitoring through wearable and ambient sensors: exemplars from home-based care of elderly with mild dementia

Monitoring and timely intervention are extremely important in the continuous management of health and wellness among all segments of the population, but particularly among those with mild dementia. In relation to this, we prescribe three design principles for the construction of services and applications. These are ambient intelligence, service continuity, and micro-context. In this paper, we provide three exemplars from our research and development activities that illustrate the use of these design principles in the construction of services and applications. All the applications are drawn from the field of care for mild dementia patients in their living quarters.     

Transformations of glycyrrhizic acid. VIII. Synthesis of immunomodulating glycopeptides using tert-butyl amino acid esters

Triterpene glycopeptides, derivatives of glycyrrhizic acid, were synthesized with the use of tert-butyl esters of L-amino acids. The condensation of glycoside with esters was carried out with N-hydroxysuccinimide--N,N-dicyclohexylcarbodiimide or N-hydroxybenzotriazol--N,N'-dicyclohexylcarbodiimide in the presence of a base (triethylamine, N-methyl- or N-ethylmorpholine). The protection groups were removed with the use of trifluoroacetic acid.